This International Standard specifies methods of calculating the theoretical quantity of outdoor air required in cargo spaces of ships where vehicles with internal combustion engines are driven, in order to dilute the polluted air to within the permitted occupational exposure limits. Annex A specifies average values of the amounts of pollutants in exhaust gases from vehicles with internal combustion engines driven in cargo spaces in ships. Annex В gives general information and guidance as to good practice for the ventilation of cargo spaces in ships where vehicles with internal combustion engines may be driven. Users of this International Standard should note that, while observing the requirements of the standard, they should at the same time ensure compliance with such statutory requirements, rules, and regulations as may be applicable to the individual ship concerned. Users should also refer to guidelines developed by the International Maritime Organization (IMO) contained in the Maritime Safety Committee Circular 729 (MSC Circ. 729), Guidelines and Recommendations for Ventilation systems in RO-RO Cargo Spaces.